Restructuring - Summary of Restructuring Activities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Reserve [Roll Forward]
Accrual as of beginning of period	$ 71.8	$ 50.2	$ 44.3
Charges	63.6	81.1	107.0
Utilization, Cash	(56.7)	(53.6)	(100.6)
Utilization, Non-cash	(4.7)	(5.9)	(0.5)
Accrual as of end of period	74.0	71.8	50.2
Employee termination benefits
Restructuring Reserve [Roll Forward]
Accrual as of beginning of period	66.5	45.1	38.7
Charges	54.1	70.0	88.6
Utilization, Cash	(51.2)	(48.6)	(82.2)
Utilization, Non-cash	0.0	0.0	0.0
Accrual as of end of period	69.4	66.5	45.1
Asset impairments
Restructuring Reserve [Roll Forward]
Accrual as of beginning of period	0.0	0.0	0.0
Charges	4.7	3.9	0.5
Utilization, Cash	0.0	0.0	0.0
Utilization, Non-cash	(4.7)	(3.9)	(0.5)
Accrual as of end of period	0.0	0.0	0.0
Contract termination costs
Restructuring Reserve [Roll Forward]
Accrual as of beginning of period	5.3	5.1	5.6
Charges	0.1	1.7	0.5
Utilization, Cash	(0.8)	(1.5)	(1.0)
Utilization, Non-cash	0.0	0.0	0.0
Accrual as of end of period	4.6	5.3	5.1
Other related costs
Restructuring Reserve [Roll Forward]
Accrual as of beginning of period	0.0	0.0	0.0
Charges	4.7	5.5	17.4
Utilization, Cash	(4.7)	(3.5)	(17.4)
Utilization, Non-cash	0.0	(2.0)	0.0
Accrual as of end of period	$ 0.0	$ 0.0	$ 0.0